Microwave radiation will be used to accomplish brain enzyme inactivation times of 1.5 seconds in the rat and 0.3 seconds in the mouse. Using this technique, studies of intermediary metabolism, cyclic nucleotide and the cholinergic system in whole brain and brain areas will be carried out. The effect of morphine will then be studied in this system. Further works will be done to decrease the microwave exposure time and to adapt the system to sacrifice unrestrained rats.